Last fall, the United States was brutally thrust into a new and dangerous world. As the twin towers of the World Trade Center collapsed and the Pentagon burned, the horrible reality of terrorism seared the American consciousness. It touched more than the victims and their families; everyone who sat transfixed before the horrific images on TV lived through the trauma. In a sense, we were all eyewitnesses, and we must all cope with feelings of anger, stress, and anxiety. That poses a huge immediate challenge for business, because it is largely in the workplace--where we spend so many of our waking hours--that we will confront these emotions. And many companies have risen to the challenge, establishing new guidelines for processing mail in light of anthrax fears and organizing stress reduction programs for employees. While the logic of taking such action is incontestable, it raises a much larger question: What responsibility does a company bear for the mental well-being of its work-force? If companies help employees deal with depression and anxiety in the wake of terrorist acts, doesn't that put mental health care on the business agenda? To answer these questions, HBR senior editor Diane Coutu talked with Dr. Steven Hyman, the former director of the National Institute for Mental Health. In this interview, he discusses the implications of coping with tragedy, the resilience of individuals, and the treatment of mental illness. And he suggests that September 11, 2001, may come to be seen as a tipping point--the moment when managers started to think about dealing with mental health issues on a regular basis.